using AsbCloudApp.Data;
using AsbCloudApp.Data.DetectedOperation;
using AsbCloudApp.Data.Subsystems;
using AsbCloudApp.Requests;
using AsbCloudApp.Services;
using AsbCloudApp.Services.Subsystems;
using AsbCloudDb;
using AsbCloudDb.Model;
using AsbCloudDb.Model.Subsystems;
using Mapster;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace AsbCloudInfrastructure.Services.Subsystems
{
#nullable enable
    internal class SubsystemOperationTimeService : ISubsystemOperationTimeService
    {

        private readonly IAsbCloudDbContext db;
        private readonly IWellService wellService;
        private readonly ICrudService<SubsystemDto> subsystemService;
        private readonly IDetectedOperationService detectedOperationService;
        public SubsystemOperationTimeService(IAsbCloudDbContext db, IWellService wellService, ICrudService<SubsystemDto> subsystemService, IDetectedOperationService detectedOperationService)
        {
            this.db = db;
            this.wellService = wellService;
            this.subsystemService = subsystemService;
            this.detectedOperationService = detectedOperationService;
        }

        /// <inheritdoc/>
        public async Task<int> DeleteAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {
            var well = await wellService.GetOrDefaultAsync(request.IdWell, token);
            if (well?.IdTelemetry is null || well.Timezone is null)
                return 0;
            var query = BuildQuery(request);
            if (query is null)
                return 0;
            db.SubsystemOperationTimes.RemoveRange(query);
            return await db.SaveChangesAsync(token);
        }

        /// <inheritdoc/>
        public async Task<IEnumerable<SubsystemOperationTimeDto>?> GetOperationTimeAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {
            var well = await wellService.GetOrDefaultAsync(request.IdWell, token);
            if (well?.IdTelemetry is null || well.Timezone is null)
                return null;
            
            var query = BuildQuery(request);
            
            if (query is null)
                return null;

            IEnumerable<SubsystemOperationTime> data = await query.ToListAsync(token);

            if (request.SelectMode == SubsystemOperationTimeRequest.SelectModeInner)
            {
                if (request.GtDate is not null)
                    data = data.Where(o => o.DateStart >= request.GtDate.Value);

                if (request.LtDate is not null)
                    data = data.Where(o => o.DateEnd <= request.LtDate.Value);
            }
            else if (request.SelectMode == SubsystemOperationTimeRequest.SelectModeTrim)
            {                
                var begin = request.GtDate?.ToUtcDateTimeOffset(well.Timezone.Hours);
                var end = request.LtDate?.ToUtcDateTimeOffset(well.Timezone.Hours);
                data = Trim(data, begin, end);      
            }

            var dtos = data.Select(o => Convert(o, well));
            return dtos;
        }

        /// <inheritdoc/>
        public async Task<IEnumerable<SubsystemStatDto>?> GetStatAsync(SubsystemOperationTimeRequest request, CancellationToken token)
        {
            request.SelectMode = SubsystemOperationTimeRequest.SelectModeTrim;
            var data = await GetOperationTimeAsync(request, token);
            if (data is null)
                return null;

            var detectedOperationsRequest = new DetectedOperationRequest()
            {
                IdWell = request.IdWell,
                IdsCategories = new List<int>() {
                  1,3
                },
                LtDate = request.LtDate,
                GtDate = request.GtDate,
            };
            var detectedOperations = await detectedOperationService.GetOperationsAsync(detectedOperationsRequest, token);
            if(detectedOperations?.Any() != true)
                return null;
            var depthInterval = GetDepthInterval(detectedOperations);

            var statList = CalcStat(data,depthInterval,request, token);
            return statList;
        }

        private static IEnumerable<SubsystemOperationTime> Trim(IEnumerable<SubsystemOperationTime> data, DateTimeOffset? gtDate, DateTimeOffset? ltDate)
        {
            var items = data.Select((item) =>
            {
                if (gtDate.HasValue && item.DateStart < gtDate.Value)
                {
                    item.DateStart = gtDate.Value;
                    item.DepthStart = null;
                }
                if (ltDate.HasValue && item.DateEnd > ltDate.Value)
                {
                    item.DateEnd = ltDate.Value;
                    item.DepthEnd = null;
                }
                return item;
            });

            return items;
        }

        private IEnumerable<SubsystemStatDto> CalcStat(IEnumerable<SubsystemOperationTimeDto> dtos, (double depthIntervalRotor, double depthIntervalSlide) depthInterval, SubsystemOperationTimeRequest request, CancellationToken token)
        {
            var groupedDataSubsystems = dtos
                .GroupBy(o => o.IdSubsystem);
            var periodGroupTotal = dtos.Sum(o => (o.DateEnd - o.DateStart).TotalHours);
            
            var result = groupedDataSubsystems.Select(g =>
            {
                var depthIntervalSubsystem = GetDepthIntervalSubsystem(g.Key, depthInterval);
                var periodGroup = g.Sum(o => (o.DateEnd - o.DateStart).TotalHours);
                var periodGroupDepth = g.Sum(o => o.DepthEnd - o.DepthStart);                
                var subsystemStat = new SubsystemStatDto()
                {
                    IdSubsystem = g.Key,
                    SubsystemName = subsystemService.GetOrDefault(g.Key)?.Name ?? "unknown",
                    UsedTimeHours = periodGroup,                    
                    KUsage = periodGroupDepth / depthIntervalSubsystem,
                    SumDepthInterval = periodGroupDepth,
                    OperationCount = g.Count()                    
                };
                if(subsystemStat.KUsage > 1)
                    subsystemStat.KUsage = 1;
                return subsystemStat;
            });

            return result;
        }
        private (double depthIntervalRotor, double depthIntervalSlide) GetDepthInterval (IEnumerable<DetectedOperationDto> detectedOperations)
        {            
             
            var depthIntervalRotor = detectedOperations.Where(o => o.IdCategory == 1)
                    .Sum(o => o.DepthEnd - o.DepthStart);
            var depthIntervalSlide = detectedOperations.Where(o => o.IdCategory == 3)
                    .Sum(o => o.DepthEnd - o.DepthStart);
            var depthInterval = (depthIntervalRotor, depthIntervalSlide);

            return depthInterval;
        }
        private double GetDepthIntervalSubsystem(int idSubsystem, (double depthIntervalRotor, double depthIntervalSlide) depthInterval)
        {
            var depthIntervalSubsystem = 0d;
            //AKB - MSE
            if (idSubsystem == 1 | idSubsystem == 2)
            {
                depthIntervalSubsystem = depthInterval.depthIntervalRotor + depthInterval.depthIntervalSlide;
            }
            //Spin
            if (idSubsystem == 65536)
            {
                depthIntervalSubsystem = depthInterval.depthIntervalSlide;
            }
            //Torque
            if (idSubsystem == 65537)
            {
                depthIntervalSubsystem = depthInterval.depthIntervalRotor;
            }
            return depthIntervalSubsystem;

        }

        private IQueryable<SubsystemOperationTime>? BuildQuery(SubsystemOperationTimeRequest request)
        {
            var well = wellService.GetOrDefault(request.IdWell);
            if (well?.IdTelemetry is null || well.Timezone is null)
                return null;

            var query = db.SubsystemOperationTimes
                .Include(o => o.Subsystem)
                .Where(o => o.IdTelemetry == well.IdTelemetry)
                .AsNoTracking();

            if (request.IdsSubsystems?.Any() == true)
                query = query.Where(o => request.IdsSubsystems.Contains(o.IdSubsystem));

            // # Dates range condition
            //           [GtDate                  LtDate]
            //      [DateStart   DateEnd]  [DateStart  DateEnd]
            if (request.GtDate.HasValue)
            {
                DateTimeOffset gtDate = request.GtDate.Value.ToUtcDateTimeOffset(well.Timezone.Hours);
                query = query.Where(o => o.DateEnd >= gtDate);
            }

            if (request.LtDate.HasValue)
            {
                DateTimeOffset ltDate = request.LtDate.Value.ToUtcDateTimeOffset(well.Timezone.Hours);
                query = query.Where(o => o.DateStart <= ltDate);
            }

            if (request.GtDepth.HasValue)
                query = query.Where(o => o.DepthEnd >= request.GtDepth.Value);

            if (request.LtDepth.HasValue)
                query = query.Where(o => o.DepthStart <= request.LtDepth.Value);

            if (request?.SortFields?.Any() == true)
            {
                query = query.SortBy(request.SortFields);
            }
            else
            {
                query = query
                    .OrderBy(o => o.DateStart)
                    .ThenBy(o => o.DepthStart);
            }

            if (request?.Skip > 0)
                query = query.Skip((int)request.Skip);

            if (request?.Take > 0)
                query = query.Take((int)request.Take);
            else
                query = query.Take(3000);

            return query;
        }

        private static SubsystemOperationTimeDto Convert(SubsystemOperationTime operationTime, WellDto well)
        {
            var dto = operationTime.Adapt<SubsystemOperationTimeDto>();
            dto.DateStart = operationTime.DateStart.ToRemoteDateTime(well.Timezone.Hours);
            dto.DateEnd = operationTime.DateEnd.ToRemoteDateTime(well.Timezone.Hours);
            return dto;
        }
    }
#nullable disable
}